The value displayed in the About Program Manager dialog box is the combined available memory, which includes installed RAM plus virtual memory. Virtual memory uses space on your hard disk to act like additional real memory through the use of swap files. We recommend having at least 16 MB of available memory (more for large models) before starting TopRank. The more installed RAM you have, the faster your simulations will run. However, you can supplement the installed memory by increasing your virtual memory settings through the Windows Control Panel, which will increase the amount of available memory as shown in the About Program Manager dialog box. Please consult your Windows manual for information about increasing virtual memory, including differences between permanent (recommended) and temporary types, and note that you must have available hard disk space in order to increase this setting.